Chapter 9 The Hydrosphere

The Hydrosphere Nature of Water The Hydrologic Cycle The Oceans Permanent Ice Surface Waters Underground Water

Water is critical to every living organism in the biosphere! Water is a part of all living things on earth. There is even water in rocks.

Earth Moisture Inventory

Three States of Water

A Water Molecule - Sticky Water H = 1 electron Not satisfied, it needs 2 O = 8 electrons Not satisfied, it needs 10 Each H atom shares its 1 e with O, and O shares 1 of its 6 outer e’s with H NOW BOTH ARE SATISFIED

Water Properties Sticky – surface tension Holds heat or cold Is liquid at normal temperatures Excellent solvent Is subject to gravity, but can move upwards – capillary action

Hydrologic Cycle Evaporation Transpiration Vertical & Horizontal Transport Earth has had the same amount of moisture for 100,000’s of years. But, it is not always stored in the same form (state). It can be stored as liquid, as vapor or as ice.

Hydrologic Cycle The annual precipitation for earth is more than 30 times the atmosphere's total capacity to hold water. This indicates the rapid recycling of water that occurs between earth's surface and the atmosphere. .001 % 2.4 % 97.5 %

Evaporation Water is transferred from the surface to the atmosphere. It is the process by which water changes from a liquid to a gas. Approximately 80% of all evaporation is from the oceans, the remaining 20% from inland water and vegetation. Winds transport evaporated water around the globe. Transport influences the humidity of the air throughout the world.

Condensation The change of water from its gaseous form (water vapor) into liquid water. Generally occurs in the atmosphere, when warm air rises, cools and loses its capacity to hold water vapor. As a result, excess water vapor condenses to form cloud droplets.

Transport by Advection The movement of water through the atmosphere, specifically from over the oceans to over the land. Some of the earth's moisture transport is visible as clouds, which consist of ice crystals and/or tiny water droplets. Clouds are propelled from one place to another by the Jet Stream or surface-based circulations. Most water is transported in the form of water vapor.

Precipitation The primary mechanism for transporting water from the atmosphere to the surface of the earth. There are several forms of precipitation: - rain (most common United States) - hail - snow - sleet - freezing rain

Hydrologic Cycle Definitions Evaporation: the conversion of liquid water on Earth’s surface lifted into the atmosphere as a gas. Advection (transport): transport of water vapor around the globe in the atmosphere Precipitation: transfer of water from the atmosphere back to earth. Ground transport: movement of water on surface and underground (always trying to get back to the ocean)

The Hydrologic Cycle Vertical: Evaporation Transpiration Precipitation Horizontal: Transport = Advection Surface Runoff Sub-surface run-off

Moisture Balance Oceans Versus Continents

Oceans 4 Oceans: Characteristics: Pacific Movement: Atlantic Indian Density: varies with temp, salinity, and depth Temp: 80°F at the equator to 28°F in Arctic & Antarctic Salinity: chemical = 35ppt Movement: Tides: 6 hrs/day water rises & 6 hrs/day water falls Currents: variety of currents shift water vertically and horizontally Waves: movement of energy more than matter 4 Oceans: Pacific Atlantic Indian Arctic

Oceans and Seas Figure 9-6

Permanent Ice Ice on land: Glaciers Permafrost Ice floating on ocean:

Glaciers

Extent of Permafrost Encircles the North Pole Continuous permafrost at 60°N and higher

Earth’s Largest Ice Pack No land/continent under the Arctic It is ice floating on water

Surface Water Lakes: Swamps & Marshes: Rivers & Streams: not permanent features Not made by, but maintained by streams Fresh water and salt water Swamps & Marshes: Closely related to lakes, but less numerous and contain less water Swamps have trees Marshes have grasses and rushes Rivers & Streams: Any flowing water is a stream Dynamic component of the hydrologic cycle

World’s Largest Lakes

Major Drainage Basins Figure 9-18

Underground Water More than 2.5 times that contained in lakes & streams More widely distributed Porosity is percentage of pores (spaces)/total volume of matter. The more porous the material, the more water it can hold. Aquifers and Aquicludes Zone of Saturation Water Table Cone of Depression Zone of Confined Water Artesian Systems The Ogallala Aquifer

Aquifer Aquiclude Underground water is stored in, and moves slowly through permeable rocks. This layer is called an aquifer. Rate of flow varies with situation. Impermeable materials i.e., clay or very dense rock, prevent water movement This layer is an aquiclude.

Zones Zone of Aeration: Zone of Saturation: Zone of Confined Water: Closest to the surface Contains clay particles and soil moisture Zone of Saturation: Below zone of aeration All openings in bedrock or sediments are saturated with water Zone of Confined Water: below zone of saturation Impermeable layer – aquiclude – below surface prevents water from percolating down Water comes in from the sides Waterless Zone: Overlying pressure increases density of rock to the point that no pores exist – no room for water.

Cone of Depression In the zone of saturation Well fills with water to level of water table If water removed faster than replenished, it collapses

Artesian System Dug below aquiclude Confined aquifer Pressure forces water up

Artesian Well

The Ogallala Aquifer Classic example of ground water mining Largest U.S. aquifer Located southern & central Great Plains Water accumulating for 30,000 years In 1950, it contained 456 trillion gallons of water It will be dry in 10 – 50 years, depending on location